I've spent millions and millions of credits trying to get a good hero. Out of all these go's I've consistently got a 'Soldier' on every single first pick.

The only time I did managed to get a Purple Hero was when 3 popped up in the selection - I 'picked' the 2 soldiers first - no surprise then cos I spent the extra Gems it had to give me one (Alexa) as my last pick.

There must be some 'weighting' factor involved to influence the chances of selecting a decent hero, obviously with the odds greatly against you.

However, I still try, but don't hold out any real hope of getting decent hero's. (I will be guaranteed a Leader Card @ lvl60 as this is one of the completion bonuses)